In recent years, many vehicles are provided with a navigation apparatus that provides travel guidance for the vehicle to allow a driver to easily reach a desired destination location. The navigation apparatus is a device that can detect the current position of the vehicle using a GPS receiver or the like and acquire map data corresponding to the current position from a storage medium such as a DVD-ROM or an HDD or through a network to display the map data on a liquid crystal monitor. Furthermore, such a navigation apparatus is provided with a route search function for searching for an optimum route from the vehicle position to a desired destination location when such a destination location is input, and adapted to set the optimum route found in the search as a route for guidance, display the route for guidance on a display screen, and provide audio guidance in the case where the vehicle approaches an intersection or the like in order to reliably guide a user to the desired destination location. In recent years, in addition, some cellular phones, smartphones, tablet terminals, personal computers, and so forth also have a function that is similar to that of the navigation apparatus described above.
With the route search function described above, in addition, a search is performed for an optimum route on the assumption of transfer with switching between a plurality of transfer means (such as walking, private car, bus, and railroad, for example), rather than a search is performed for an optimum route simply from a departure location to a destination location (see Japanese Patent Application Publication No. 2000-258184 (JP 2000-258184 A) and Japanese Patent Application Publication No. 2012-58157 2012-58157 A), for example).